ANALYSIS OF THE PROBABILITY AND RISK OF CAUSE-SPECIFIC FAILURE

Purpose: Kaplan-Meier curves are frequently misused in the analysis of nonsurvival endpoints, such as time to local failure or time to late complications. More appropriate analyses are available and described. Methods and Materials: Cumulative incidence is an unbiased estimate of probability of cause-specific failure. Cumulative conditional probabi lity of cause-specific failure reflects risk to patients remaining at risk. Hazard rates also measure risk. Results: Kaplan-Meier curves ove restimate the probability of late complications when there is a high m ortality rate. Cumulative incidence and cumulative conditional probabi lity accurately give the probability and risk of cause-specific failur e. Conclusion: Kaplan-Meier analysis of cause-specific failure should be avoided because of its misinterpretation as an estimate of probabil ity, in favor of appropriate methods.